Hardness tester



Aug- 3.1, 1948- M. A. CHESTER 2,448,486

HARbNEss' TESTER Filed Dec. 29, 1944 BY y 27 W3/'a Wl Patented Aug.. 3l,1948 vUNITED STATES PATENT OFFICE y HARDNESS TESTER Milton A. Chester,Wichita, Kans.

Application December 29, 1944, Serial No. 570,393

20 Claims. (Cl. Z3-81) The invention herein disclosed relates toinstruments for testing and determining the hardness and strength ofvarious materials.

Special objects, of the invention are to provide an instrument of thecharacter indicated, of small size, adapted to be vcarried in the handor in the pocket, readily applicable to the pieces or material to betested and accurate and reliable in its operation.

Additional objects are Vto provide the instrument in a simple,inexpensive form, quickly and easily understood and used.

Other desirable objects and the novel features of invention by which theabove and other purposes are attained, are set forth orwill appear inthe course of the following specication.

The drawing accompanying and forming part of the speciiicationillustrates a present commercial embodiment of the invention. Structure,however, may be modiiied and changed as regards the presentillustration, all within the true intent and broad scope of theinvention as hereinafter dened and claimed.

Fig. 1 in the drawing is a plan view of an embodiment oi the invention;

Fig. 2 is a side elevation and broken sectional view with parts shown inthe position of first clamping the piece and before setting thepenetrator point in contact with the material,

Fig. 3 is a broken sectional detail similar to Fig. 2 but with` thefollow-up spindle shown turned inward to 4advance the penetrator intoengagement with the piece;

Fig. 4 is a similar view showingthe hand lever opened out and the springload applied to the penetrator;

Fig. 5 is a vertical sectional view as on substantially the plane ciline 5-5 of Fig. 2; and

Fig. 6 is a fragmentary sectional view` of a structural detail.

The body of the device is shown in the form of a yoke l in the nature ofa C clamp having the spaced sides or arms 8. 9, connected in such spacedrelation by the back portion I Il.

A screw shaft II is shown operating through one arm, 8, having a handleI2 at the outer end and an anvil or clamp element I3 at the inner end,the latter ln opposition to a nat or other desirably shaped fixedclamping face I4.

A penetrator is shown in the form of a plunger I5 operable in a bore I6and having a penetrating point I1 projectable through an opening I8 inthe material engaging and clamping face I I. The plunger is shown ashaving a reduced front end portion I9 guided in the opening I8. A spring2 28 about this reduced front end portion serves to retract and tonormally hold the plunger retracted in the position indicated in Fig. 2.

The opposite end portion of the penetrator plunger is shown reduced at2I. providing an annular shoulder 22 engageable by the forked inner end23 of a lever 24 iulcrumed at 25 and engaged at its outer end at 26 by aspring 21,

With the leverage provided as indicated, the spring 21 may be relativelyshort and compact and small enough to be completely housed withinachamber 28 provided in the back or connecting portion of the yoke, toone side of and substantially parallel with the axis of pressure appliedby the tool.

The spring load is applied to or removed from the penetrator in theillustration by a hand lever 28 fulcrumed on the body of the tool at 38.substantially in line with the axis of the spring and carrying a cam inthe form of an eccentric 3| bearing on the long arm of the leversubstantially in line with the pOint of engagement of the lever with thespring.

The hand lever is shown as hollowed at4 32 to flt closely about the backof the yoke, over the spring housing therein, and the closing movementof the lever is indicated as suiiicient to carry the eccentric to orbeyond dead center position so as to eilect holding of the handle in theunloaded position illustrated in Fig. 2.

An initial setting of the penetrator in respect to the material iseffected. in the illustration, by means of a follow-up spindle 33rotatably supported in a bearing 34 in the yoke in line with thepenetrator plunger and having a rounded bearing point 35 on its innerend for engagement with the end of the spindle.

In the present illustrated embodiment oi the invention, the spindle 33has a screw engagement in the yoke by which it can be turned intoengagement with the penetrator plunger and operated to adjust and setthe penetrator into exact contact with the piece under test.

The screw adjustment referred to is provided in the illustration byconstruction of the spindle with a screw threaded inner end portion 38engaging in a corresponding screw threaded bore in a worm gear 31. Thelatter is shown rotatably seated and centered against endwise movementbetween a thrust washer 38 and the inner rotary element of a balibearing 39.

Fig. 3 shows how, after the piece under test is clamped in theinstrument, the spindle may be screwed through the worm gear to engagethe inner end of the plunger and force the latter outtimes.

ward sulllciently to carry the penetrator point into positive engagementwith the piece.

The spindle is shown as having a fixed finger hold 40 on the outer endportion of the same, with a slip thimble 4| rotatably engaged partlythereovcr and frictlonally controlled by an en- :losed helical spring 42caught to the spindle at its inner end.

After the preliminary or initial engagement of the penetrator with thepiece is eiected, as in Fig. 3, the handle 29 may be opened out as shownv in Fig. 4 to relieve the lever 24 of control by the cam and permitapplication of the full spring force to the penetrator point.

In such advancement the penetrator plunger will leave the end of thefollower spindle and the extent of such separation is utilized in theillustration as a. measure oi' the penetration.

This further or follow-up movement of the spindle is accomplished in theexample shown, by worm 43 in engagement with the worm gear 31 andcarried by a vertically extending spindle 44 having a handle or knob 45carrying a pointer 4B registering with micrometer markings 41 on a dial48. A yieldingly held slip thimble 49 is shown rotatably engaged on theworm spindle 44 similar to that provided at 4| on the outer end of thefollow-up spindle.

In addition to or in place of the off-center disposition, the cam oreccentric may have a slightly flattened area 3|a for releasablyretaining the handle in the folded position shown in Figs. 2 and 3. Thishand lever permits the load from the spring to be gradually applied andenables an exact control of the operation at all Instead of a plaineccentric as shown, the cam may be shaped to automatically provide anydesired action.

The retracting spring 20 holds the penetrator point housed and protectedwhen not in use.

The invention provides a compact, pocket size tester, accurate forquantitative determination of hardness, and the worm operated micrometerscrew provides easily read ne measurements.

The spring provides a constant load and the hand lever and cam aiford aconveniently operable means for applying and disconnecting that load.

The markings on the micrometer scale may be in terms of hardness orother values. The anvil or clamping element I3, instead of being fiat asindicated, may be notched, grooved or otherwise shaped to hold circularor other shaped pieces.

To enable ready assembly, removal and replacement of the penetrator andthe substitution of diiferent types or forms of penetrators fordiiferent kinds of materials, relative hardness, etc., the outer end ofthe guide passage for the penetrator may be provided by a cover 50, Fig.6, removably engaged in a screw seat 5| and provided with recesses 52,or the like for engagement by a spanner or other tool. This covercarries the guide opening for the point of the penetratorl serves as theabutment for the retracting spring 28 and has the outer face of the samefinished to form the material engaging reference surface |4. Thisexposed face may be curved, groovecl, or otherwise shaped, the readyremovability of the cover enabling quick substitution of covers withsuch different face shapes.

What is claimed is:

1. A hardness tester comprising a base having a reference faceengageable with the piece to be tested, a penetrator on said base andmovable thereon from a non-protruding to a protruding position, meansfor adjustably advancing said penetrator with respect to -said referenceface from a non-protruding position into engagement with the piece,spring means for forcing the penetrator from said adjustably advancedposition into the piece, and means for measuring the movement of saidpenetrator from said adjustably advanced position and for indicating thevalue of the penetration so effected.

2. A hardness tester comprising a base having a. reference faceengageable with the piece to be tested, a penetrator movably mounted onsaid base, spring means for normally holding said penetrator inretracted position in respect to said reference face, means foradjustably advancing the penetrator into engagement with the piece,spring means on the base for forcing the penetrator from said adjustablyadvanced position into the piece, and means on the base for indicatingthe value of penetration so effected.

3. A hardness tester comprising a yoke having sides spaced to embracethe piece to be tested. a clamp member adjustable in one side of theyoke to clamp the piece against the other side of the yoke, a penetratoradjustable in said other side of the yoke toward and away from saidclamp member, a spring for holding said penetrator in normally retractedposition, means for setting said penetrator into contact with the pieceunder test, spring means on the yoke for forcing the penetrator into thepiece, means for indicating value of the penetration so effected, and ahand lever arranged to effect the application and the release of thepower of said spring means in respect to said penetrator.

4. A hardness tester comprising a base, a penetrator plunger operable onsaid base, a spring acting to hold said plunger in retracted position, ascrew spindle at the back of'said plunger and adjustable to advance thesame into engagement with a piece to be tested, spring means forforcefully advancing the penetrator plunger, and indieating meansadjustable to advance said spindle into engagement with the plunger inits advanced position.

5. A hardness tester comprising a base, a penetrator plunger operable onsaid base, a spindle ,rotatably mounted on the base at the back of 6. Ahardness tester comprising a base, a penetrator plunger operable in saidbase, a worm g'ear rotatably mounted in the base at the back of saidplunger, a spindle having a screw engagement in said worm gear andadapted by rotation therein to be advanced into engagement with saidpenetrator spindle, an indicator worm in engagement with said worm gear,and spring means on the base for applying a penetrating force to saidpenetrator plunger.

'7. A hardness tester comprising a base, a penetrator plunger operatingin said base, a lever fulcrumed on said base and engageable with saidplunger at one end, a spring operable on the other end of said lever, ahand lever fulcrumed on the base and having a cam portion engaged tionedlever, and means on said base for indieating values related to theextent of penetration accomplished by said penetrator plunger.

8. A hardness tester comprising a yoke having spaced arms connected by aback portion, said back portion having a spring cavity therein, anexpansion spring housed in said cavity, a 'penetrator plunger operatingin one of the arms of said yoke, a lever fulcrumed on said arm andextendingfrom said spring to said plunger, a hand lever fulcrumed insaid arm and having an eccentric operating on the end of the leverengaged with the spring, and penetration indicating means associatedwith said penetrator plunger.

9. A hardness tester comprising a yoke having spaced arms connected by aback portion, said back portion having a spring cavity therein, anexpansion spring housed in said cavity. a Penetrator plunger operatingin one of the arms of said yoke, a lever fulcrumed on said arm andextending from said spring to said plunger, a hand lever fulcrumed insaid arm and having an eccentric operating on the end of the leverengaged with the spring, and penetration indicating means associatedwith said penetrator plunger, said lever having a one-way drivingengagement with the penetrator plunger for projecting the same andspring means for eiecting retraction of said plunger.

10. A hardness tester comprising a yoke having spaced arms connected bya back portion, said back portion having a spring cavity` therein, anexpansion spring housed in said cavity, a penetrator plunger operatingin one of the arms of said yoke. a lever fulcrumed'on said arm andextending from said spring to said plunger, a hand lever fulcrumed insaid arm and having an eccentric operating on the end of the leverengaged with the spring, and penetration indicating means associatedwith said penetrator plunger, a follow-up spindle in back of saidplunger for advancing said plunger into engagement with a piece to betested, and said indicating means including mechanism for advancing saidspindle into engagement with the penetrator plunger in its position ofadvancement by the spring means aforesaid.

11. A hardness tester comprising a, base. a penetrator plunger operablein said base and normally supported in a non-projecting position,

Y a lever fulcrumed on the base and engaging said Iplunger at one end toshift the same in proin engagement with said spring lever to effectspring loading and unloading of the penertator plunger, and means forindicating results of penertation effected by said penetrator plunger12. A hardness tester comprising a C clamp having a movable anvil in oneside and a penetrator in the opposite side, a spring housed within thebody of said C clamp, a lever operable within the body of the clamp andextending from said spring to said penetrator, and a handle pivoted onthe body of said c` clamp and having a cam portion engageable with saidlever for controlling spring loading and unloading of said penetrator.

13. A hand portable hardness tester comprisa lever for projecting saidpenetrator, a spring housed within the body of the c clamp at one sideof the jaw portion of the same and engaging said lever. a hand leverfuicrumed on the body portion of the clamp over the spring housedtherein and having an eccentric portion engageable with the springactuated lever for controlling spring loading and unloading of the,penetrator, and indicating means associated with the penetrator.

14. A hand portable hardness tester comprising a small pocket size cclamp having opposed jaws relatively adjustable for clamping a. piece tobe tested, a normally non-projecting penetrator operating through theface of one of the jaws, a lever for projecting said penetrator. aspring housed within the body of the c clamp at one side of the jawportion of the same' and engaging said lever, a hand lever fulcrumed onthe body portion of the clamp over the spring housed therein and havingan eccentric portion engageable with the spring actuated lever forcontrolling spring loading and unloading of the penetrator, andindicating. means associated with the penetrator and including afollow-up spindle for eiecting initial engagement of the penetrator withthe piece to be tested, and mechanism sensible to the extent ofadjustment necessary to carry the follow-up spindle from the initialsetting of the penetrator to the nal position of the same.

15. A hardness tester comprising a C clamp having a reference face atone side and a screw clamp operable in the other side for clamping apiece to be tested, said C clamp having a cavity in the back portion ofthe same, a spring housed in said cavity, a penetrator operable in theclamp from a non-protruding to a protruding position in respect to saidreference face, leverage means extending from said spring to saidpenetrator and hand operable means on said C clamp for storing ing asmall pocket size c clamp having opposed v and releasing the energy ofsaid spring.

16.A hardness tester comprising a C clamp having a reference face at oneside and a screw clamp operable in the other side for clamping a pieceto be tested, said C clamp having a cavity in the back portion of thesame, a spring housed in said cavity, a penetrator operable in the clampfrom a non-protruding to a protruding position in respect to saidreference face, leverage means extending from said spring to saidpenetrator, hand operable means on said c clamp for storing andreleasing the energy of said spring and hand adjustable means on said cclamp for eii'ecting projecting movements of said penetratorindependently of said spring actuated connections.

`1'1. A hardness tester comprising a base, a penetrator plungeroperating in said base, a lever fulcrumed on said base and cooperablewith said plunger to thrust it in the penetrating direction, a springmounted in said base and acting on said lever to apply the penetratingforce thereto, a hand lever fulcrumed on the base and having a camportion operative in the movement of said lever to load said penetratorplunger with and to unload it from the force of said spring and meanshand lever fulcrumed on the base and having a cam portion operative inthe movement of said lever to load said penetrator plunger with and tounload it from the force of said spring and means on said base foreiectlng a preliminary engagement of said penetrator plunger with apiece to be tested independently of the spring loading and includingfollow-up indicating mechanism operative after the loading movement toindicate plunger movement accomplished thereby.

19. A hardness tester comprising a base, a penctrator plunger operatingin said base, a lever iulcrumed on the base and operable on said plungerto effect advancement of the same in the penetrating direction, a springoperable on said lever to effect movement of the same in the plungerpenetrating direction, a cam mounted on the base for applying andremoving the electlve force of said spring in respect to said penetratorplunger, a hand lever for actuating said cam to eiect the reversefunctions of the same, a spindle in back of the plunger longitudinallyadjustable for advancing the plunger into engagement with a piece to betested and follow-up mechanism for effecting engagement of said spindlewith the plunger after the penetrating impulse applied by the spring andincluding means for indicating the extent or value of such penetratingmovement.

20. A hardness tester comprising a base, a penetrator plunger operatingin said base, a lever fulcrumed on tho base and operable on said plungerto eil'ect advancement of the same in the penetrating direction, aspring operable on said lever to effect movement of the same in theplunger penetrating direction, a cam mounted on the base for applyingand removing'the eil'ectlve force of said spring in respect to saidpenetrator plunger, a hand lever for actuating said cam to effect thereverse functions of the same, said cam having a holding portionoperable under the force of .the spring to yieldingly retain the cam andhand lever in position with the spring force free of the plunger andmeans on the base for indieating values related to the extent ofpenetration accomplished by said penetrator plunger under the force ofsaid spring.

MILTON A. CHESTER.

REFERENCES CITED The following references are of record in the ille ofthis patent:

UNITED STATES PATENTS

